by Kristen Carney
Updated: August 7, 2025
The richest county in Washington is King County with an average household income of $170,405 as of 2023 and 2,340,211 people as of 2023 according to the most current Census data available (citation).
Rank | County | Population | Average Income | Median Income |
---|---|---|---|---|
1 | King County | 2,340,211 | $170,405 | $122,148 |
2 | Snohomish County | 864,113 | $136,089 | $107,982 |
3 | San Juan County | 18,668 | $129,398 | $83,682 |
4 | Kitsap County | 281,420 | $125,517 | $98,546 |
5 | Clark County | 527,269 | $120,560 | $94,948 |
6 | Pierce County | 941,170 | $120,501 | $96,632 |
7 | Benton County | 218,190 | $111,832 | $87,316 |
8 | Thurston County | 302,912 | $111,383 | $93,985 |
9 | Douglas County | 45,795 | $110,625 | $80,374 |
10 | Island County | 86,478 | $110,452 | $88,358 |
11 | Skagit County | 132,736 | $108,032 | $85,474 |
12 | Skamania County | 12,660 | $106,938 | $90,085 |
13 | Whatcom County | 234,954 | $105,948 | $80,989 |
14 | Chelan County | 81,228 | $105,534 | $78,306 |
15 | Franklin County | 101,238 | $105,287 | $82,755 |
16 | Jefferson County | 33,944 | $101,205 | $71,143 |
17 | Spokane County | 555,947 | $98,513 | $73,513 |
18 | Mason County | 69,632 | $97,813 | $78,359 |
19 | Klickitat County | 24,124 | $96,485 | $70,400 |
20 | Walla Walla County | 62,068 | $96,277 | $72,212 |
We usually suggest using median income data – either instead of or in addition to – average income data as a true indicator of wealth. If you haven’t thought about median versus average since your last standardized test, you aren’t alone. Here’s what they are:
Now let’s say you had the following simplified set of income data.
Household 1: $30,000
Household 2: $50,000
Household 3: $1,000,000
The average income for this set is $360,000. The outlier data point ($1,000,000) skews the average WAY up. Conversely, the average income would be skewed WAY down if someone had an income of $500. The median income for the same data set is $50,000. Outlier data doesn’t skew the median.
So most business owners should use the median income as a true indicator of wealth, because it provides a more accurate representation of a typical income, especially in areas with significant income disparity.
If your target market is high-income households, the average income may be more relevant. This is because the average income can highlight the presence of a higher concentration of wealthy individuals, which is beneficial for luxury goods and services marketing. We’re using average income on this page because using the Census’s highest reported median value of $250,001 could result in multiple ties for the richest geography.
The Census' American Community Survey uses $250,000+ as a jam value for median income estimates to protect privacy, ensure data consistency, and simplify reporting. A "jam value" in survey data refers to a placeholder or default value used when actual data points are unavailable, incomplete, or exceed certain thresholds. We represent this jam value as $250,001 to make it easy for you to sort.
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United States Census Bureau. Annual Estimates of the Resident Population: April 1, 2020 to July 1, 2023. U.S. Census Bureau, Population Division. Web. May 2024. http://www.census.gov/.
United States Census Bureau. B01001 SEX BY AGE, 2023 American Community Survey 5-Year Estimates. U.S. Census Bureau, American Community Survey Office. Web. 12 December 2024. http://www.census.gov/.
United States Census Bureau. B19013 Median Household Income, 2023 American Community Survey 5-Year Estimates. U.S. Census Bureau, American Community Survey Office. Web. 12 December 2024. http://www.census.gov/.
United States Census Bureau. “DP03 SELECTED ECONOMIC CHARACTERISTICS.” 2023 American Community Survey 5-Year Estimates. U.S. Census Bureau, American Community Survey Office. Web. 12 December 2024. http://www.census.gov/.
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